The 20-year-old came on as a second-half substitute against Villarreal, scoring the third in a 3-1 win.
"Everyone can see what is expected of Joao, he's a young boy and he has lots of room for improvement," Koke said after the match.
"Many great players have had to adapt to Atletico and it's not easy, he's young.
"If he listens to the boss and his teammates, he will be the player that everyone wants to see.
"He's not been lucky with injuries, but I'm sure that, in the future, we'll see the Joao we want to see."
Koke scored and also produced an assist for the win.
"It's normal, the demand at Atletico is maximum," Koke said.
"It's normal that there is this time of transition.
"We've had back luck with injuries this season, I'd like to see other teams [go through] what has happened to us.
"When people are fit, it's key for us.
"The more first team players there are [that are fit], the higher the level and more competition.